层状催化剂颗粒的优化设计——双组分等温平行反应体系

针对双组分等温平行反应体系,分析讨论了以提高催化剂活性和选择性为目标时催化剂活性组分的最优分布形式(为δ-函数分布),并给出了确定这种反应体系的催化剂的最佳活性层位置的计算方法。结果表明:以提高选择性为目标的最佳活性层位置比以提高活性为目标的要更靠近催化剂核心,实用的最优位置应介于二者之间。最后,本文还研究了反应动力学级数、本性选择性以及内扩散模数(Thiele 模数)等因素对最佳活性层位置的影响。     

Construction of a control system for disturbance rejection using a dual observer

A well‐known control system which can reduce the adverse effects of disturbances is a disturbance observer. However, in many cases of mechanical systems, system disturbances which do not satisfy the matching condition may be imposed. Therefore, it may be difficult to reduce the adverse effects of the disturbances by the traditional disturbance observer. In this paper, a method of control system synthesis for disturbance rejection using a dual observer is proposed. This method is based on the zeroing induced by the disturbance localization problem. This problem may be solved by dividing the state space into observable subspace and unobservable subspace. As compared with an H_∞ controller based on perfect observation, the usefulness of the proposed control system for disturbance rejection is demonstrated by numerical simulations for a two‐mass spring system. © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 50–60, 2002; DOI 10.1002/eej.1138     

排气系统在注射模中的应用

介绍了排气系统在注射模中的重要性,排气系统位置的选择,排气系统的种类以及应用等     

Quantitative evaluation of generator power control effect of FACTS controllers for power system stabilization

The advancement of power electronics technologies has significantly developed the power system stabilizing controllers. Quantitative as well as qualitative evaluation of their effectiveness in power systems is a matter of great importance for the feasibility investigation of these apparatus. In this paper, the possible control region of FACTS controllers with series and/or shunt configuration in a single machine to infinite bus system is formulated in the powerangle curve with a set of algebraic equations. The effectiveness of TCPST (Thyristor‐Controlled Phase Shifting Transformer), SSSC (Static Synchronous Series Compensator), and TCSC (Thyristor‐Controlled Series Compensator) for the improvement of the transient stability is evaluated quantitatively as a numerical example. The correctness of the proposed method has been confirmed by analysis based on the electromagnetic transients simulation with a detailed system model. © 2001 Scripta Technica, Electr Eng Jpn, 138(3): 43–51, 2002     

Electrochemical impedance spectroscopy of a free-standing oxide film

The corrosion of low carbon steel in natural sea-water is characterized by the formation and growth of compact and thick layers composed of oxides, insoluble salts and organic materials. These layers are the result of corrosion processes induced by local environmental conditions, water oxygen supply; ionic species; bacteria and organic matter. The exchange of various species (ions, molecules, gas) between sea-water and the rust layers or the metal depends both on the kinetics of the Faradaic reactions of the entities with either the oxides or the metal, as well as on their transport properties through the different strata of the rust layers. In this work, an impedance study was carried out using the 4-electrodes cell arrangement with corrosion products picked up on steel sheet piling immersed for 25 years and analyzed as free standing membranes. This new approach is a good way to reach the specific transport and transfer properties of the oxide without being blurred by the metal influence. The physical model developed in this work was based on a transmission line, and accurately described the experimental diagrams. The electronic resistivity of the oxide layer, its porosity, the mean pore size and the reaction kinetics parameters could be determined from the fittings.     

Sensorless control of synchronous reluctance motors using on‐line parameter identification method not affected by position estimation accuracy

This paper presents a novel on‐line parameter identification method for sensorless control of Synchronous Reluctance Motors (SynRMs). Although conventional sensorless control methods based on mathematical models usually need some complex measurements of motor parameters in advance, the proposed identification method does not require them and can be realized on‐line. The proposed method identifies motor parameters under sensorless control, so rotor position and velocity cannot be used to identify these parameters. However, the proposed method does not need rotor position and velocity, and identified parameters are not affected by these estimation errors. The sensorless control using identified motor parameters is realized, and the effectiveness of the proposed method is verified by experimental results. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(3): 62–69, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20258     

A novel robust current control approach using adaptive line enhancer for three‐phase current‐source active power filter

An effective system control method is presented for applying a three‐phase current‐source PWM converter with a deadbeat controller to active power filters (APFs). In the shunt‐type configuration, the APF is controlled such that the current drawn by the APF from the utility is equal to the current harmonics and reactive current required for the load. To attain the time‐optimal response of the APF supply current, a two‐dimensional deadbeat control scheme is applied to APF current control. Furthermore, in order to cancel both the delay in the two‐dimensional deadbeat control scheme and the delay in DSP control strategy, an Adaptive Line Enhancer (ALE) is introduced in order to predict the desired value three sampling periods ahead. ALE has another function of bringing robustness to the deadbeat control system. Due to the ALE, settling time is made short in a transient state. On the other hand, total harmonic distortion (THD) of source currents can be minimized compared to the case where ideal identification of the controlled system can be made. The experimental results obtained from the DSP‐based APF are also reported. The compensating ability of this APF is very high in accuracy and responsiveness although the modulation frequency is rather low. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(1): 50–61, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20014     

攀钢“501”滑动水口液压驱动系统的研制

介绍了为攀钢“５０１”滑动水口研制的专用液压驱动系统，对该系统的工作原理，性能特点，主要元件（设备）的选择原则等作了较为详细的说明介绍。     

秦山核电厂蒸汽发生器水位控制试验

简要介绍了蒸汽发生器水位控制系统的运行方式和试验方法。试验项目包括旁通阀控制试验、主给水阀控制试验和旁通阀与主给水阀的切换试验。文中给出了试验结果,即在液位扰动和核动率扰动时,蒸汽发生器液位的变化过程。经过两个月的运行和瞬态试验,证明蒸汽发生器水位控制系统满足设计要求。